Coles Corliss Steam - Need Help

[dsenechal57]

Hi. I bought a "mostly complete" Coles Corliss engine, which arrived a couple of days ago. Overall, it seems like a solid build, from what I can tell.

I'm having a bit of a time, though, getting it to run. I believe I have the valves set correctly, but when I apply air pressure, nothing happens. From what I can see, there's no reason why it shouldn't run, but it doesn't.

Is there anyone on this forum who knows about this engine that might be able to walk me through this? Perhaps look at the way I have things set up and tell me what I might be doing wrong? I do have the plans, etc.

I would surely appreciate it.

Thank you.

Dave

 

[GreenTwin]

Do the plans list a sequence for setting up the valve timing?
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[GreenTwin]

This person adjusted his Coles Corliss.

 

[GreenTwin]

Another Corliss valve timing video:

 

[Richard Hed]

Assuming the engine turns by hand, then I am wondering if the input valves are in the correct positions?, that is, are they in the correct 180Deg position. If that looks correct, are you sure you have them in the correct left and right positions? If that is all correct, then are you sure that you have steam valves in the steam position and not the exhaust valves in that position?

Do all the mechanisms move easily? is it possible that one of the valve stems is not rocking back and forth?

 

[dsenechal57]

This person adjusted his Coles Corliss.

That's a beauty!

 

[dsenechal57]

Do the plans list a sequence for setting up the valve timing?
.

There's a 4-page addenda that supposedly does that. I think I followed the directions, but they're extremely confusing. That's why I was hoping someone in this forum might have some experience with this engine and let me know what I might be doing wrong.

 

[dsenechal57]

Assuming the engine turns by hand, then I am wondering if the input valves are in the correct positions?, that is, are they in the correct 180Deg position. If that looks correct, are you sure you have them in the correct left and right positions? If that is all correct, then are you sure that you have steam valves in the steam position and not the exhaust valves in that position?

Do all the mechanisms move easily? is it possible that one of the valve stems is not rocking back and forth?Thanks for the replauThere's a 4-page addenda to the instructions, that I believe I have followed correctly. However, they're written in such a confusing way that I'm not 100% sure.

Thanks for replying to my query, Richard.

There's a 4-page addenda with timing instructions, and I believe I have followed it correctly. However, it was written in a very confusing manner that makes it possible I did not. For example, "Schematic Valve Setting Sketch, as viewed from the back side of cylinder ass'y toward the valve wrist plate ass'y". But the wrist plate ass'y is on the FRONT. It also refers to what the valves and linkages should look like when the engine is "at rest". I have no idea what "at rest" means.

Anyway, to answer your question, I'm reasonably sure they're in the correct positions using the plans and that 4-page addenda as a guide, and based on my understanding on how the valves and linkages are supposed to work. The engine seems a little "stiff" but turns by hand without difficulty. One valve was stuck when I got it, but I got that resolved and all four move freely without binding.

There are just a lot of variables, all inter-related, and just one of which throws everything else off. I'm hoping there's someone in this forum with some experience with this engine that walk me through it and perhaps tell me what I might be doing wrong.

Thanks again for taking the time to reply!

 

[Richard Hed]

Thanks for replying to my query, Richard.

There's a 4-page addenda with timing instructions, and I believe I have followed it correctly. However, it was written in a very confusing manner that makes it possible I did not. For example, "Schematic Valve Setting Sketch, as viewed from the back side of cylinder ass'y toward the valve wrist plate ass'y". But the wrist plate ass'y is on the FRONT. It also refers to what the valves and linkages should look like when the engine is "at rest". I have no idea what "at rest" means.

Anyway, to answer your question, I'm reasonably sure they're in the correct positions using the plans and that 4-page addenda as a guide, and based on my understanding on how the valves and linkages are supposed to work. The engine seems a little "stiff" but turns by hand without difficulty. One valve was stuck when I got it, but I got that resolved and all four move freely without binding.

There are just a lot of variables, all inter-related, and just one of which throws everything else off. I'm hoping there's someone in this forum with some experience with this engine that walk me through it and perhaps tell me what I might be doing wrong.

Thanks again for taking the time to reply!

Is it possible to send me a copy of that 4 page addenda? And is it possible to send some photos of the setup?

 

[GreenTwin]

I have never set up a Corliss, but how hard can it be ?

My guess is as follows:

1. Figure out if you are trying to set the valves with the engine running over, as in the video above, and make sure you are not setting the valves for running under, which would have the flywheel rotate backwards from the video.

2. Remove the cylinder head from the end of the engine, and with a little air pressure turned on and fed into the top of the cylinder (using the normal feed point like in the video), rotate the flywheel to top dead center.
The upper valve near the cylinder head that you removed should start to admit steam either just before the piston reaches top dead center, at TDC, or slightly after TDC. If you don't hear air coming into the cylinder somewhere around TDC, adjust the gear so that that event happens (called setting the admission point).

3. Rotating the engine to bottom dead center (BDC), as you rotate towards bottom dead center, the upper valve near the flywheel should start to open somewhere just before, at, or just after BDC. Perhaps you can feel a pull on the flywheel when that valve begins to open.

4. A lower valve should start to open when the piston is about 70% down the stroke (check me on that) to release the cylinder pressure.

5. The upper valves can trip shut anywhere from 12% of stroke to some late amount of stroke, depending on how much cutoff you want.
I don't think the cutoff point is critical for an engine with no load, but when running on air, you may want a little later cutoff since air does not expand like steam.

Does this make sense?

.

 

[GreenTwin]

Also, you can slow the video above down, and observe the position of the crankshaft vs the position of the four valves.

You could possibly set the vavles to match the video.

.

 

[Richard Hed]

Another possibility is that the valves were made in reverse (end to end not side to side) . I would DEFINITELY check those valves for correctness--they are intimidating in their confuzingness. I have not completed MY valves, but just looking at the drawings I can see that one has to take EXTREME care to NOT reverse on 3 axis'.

 

[GreenTwin]

What you need to figure out is if your valvegear is set up and "in the ballpark", or if it was not set up correctly, and is way out of adjustment.

If your valve gear is way off, I think you would have to loosen the grub screw that holds the arm to the valve shaft, and rotate that joint.

If the valve gear is close to being correct, it looks like the connecting arms are threaded, and perhaps those can be adjusted.


Here is what I would call a front view of the valve gear (from the above video).

Intake valves are on the top, exhaust valves are on the bottom.

The exhaust valves are operated in a simple fashion with no dashpots.

Teh intake valve mechanism is a bit more complex I think because of the governor action.

.

 

[GreenTwin]

Much will depend on how close you are to a good valve setup.

If you are way off, then you will probably have to follow the directions step by step.

If somebody can post the directions, I can translate them.

Edit:
Maybe I have that.

.

 

[GreenTwin]

I think this is one of the diagrams in question (not my diagram).

I would assume that the right side is where the cylinder head screws on.

Exhaust valves would be at the bottom, steam valves at the top.

I would say this is the same view as I posted above.

The sequence is that the upper right steam valve opens around TDC, and as the piston moves down its stroke, the exhaust valve on the lower left has to open to relieve the pressure on the bottom of the cylinder.

The upper right valve closes at some point during the downstroke.

When the piston reaches BDC, the lower left exhaust valve is closed, the upper right valve is closed, the upper left valve opens, and the lower right valve opens, pushing the piston back up to top dead center.

 

[GreenTwin]

I don't think I have the full valve setup instructions, but from what I have, it sounds like you can perhaps disconnect the exhaust valve linkage, and open the exhaust (bottom) valves.

Then you can manipulate the upper valves and valve gear, and you can determine when the admission (upper) valves begin to open because it will blow through and out the exhaust valve(s).

So sounds like you set the admission valves first, and then the exhaust valves.

The linkage is pretty complex, and so you will have to be rather methodical about setting it.

Setting one valve at a time starting with the upper ones will be the key.

.

 

[Richard Hed]

I think this is one of the diagrams in question (not my diagram).

I would assume that the right side is where the cylinder head screws on.

Exhaust valves would be at the bottom, steam valves at the top.

I would say this is the same view as I posted above.

The sequence is that the upper right steam valve opens around TDC, and as the piston moves down its stroke, the exhaust valve on the lower left has to open to relieve the pressure on the bottom of the cylinder.

The upper right valve closes at some point during the downstroke.

When the piston reaches BDC, the lower left exhaust valve is closed, the upper right valve is closed, the upper left valve opens, and the lower right valve opens, pushing the piston back up to top dead center.



View attachment 150756

This certainly IS conphuzing. Why would anyone make a drawing that has the front backwards reversed and upside down flipped over? If one were to put in the piston rod, then one would know what is forward and reverse.

 

[dsenechal57]

Is it possible to send me a copy of that 4 page addenda? And is it possible to send some photos of the setup?

Here are the four pages. I'll send some pictures a little later this afternoon. Thank you.

 

[dsenechal57]

Also, you can slow the video above down, and observe the position of the crankshaft vs the position of the four valves.

You could possibly set the vavles to match the video.

.

That video would be useful as a guide, but I don't think it's a Coles (or at least not the Coles that I have). Your instructions (above) seem like they might bear some fruit and I'll give them a try.

 

[dsenechal57]

Much will depend on how close you are to a good valve setup.

If you are way off, then you will probably have to follow the directions step by step.

If somebody can post the directions, I can translate them.

Edit:
Maybe I have that.

.

Thanks, Here are the instructions: